Is this oil overkill?

I have a 283 sbc from a 1966 Chevelle that had been overhauled to stock specs (installed in my '57 Willys CJ5). It is running 305 heads and has 1300 miles on it so far. As far as oil goes, do I need something like this oil with added zync or will any oil suffice? I currently have Mobil 1 synthetic 10w-30 in it. Oil pressure runs around 40 cold idle and 12-15 hot idle up to 30-ish hot around 2500-300 rpm. Should I change? I live in NC and it is hot during the summer and can be cold in the winter.

AMSOIL Synthetic Motor Oil and Engine Oil

Yes, If your running a flat tappet cam you need zinc!
The Amsoil you listed in your post will work if you want to run synthetic.

Brad Penn also makes an oil with high zinc content for flat tappet engines.

Mobil One, although good, will not protect your flat tappet cam.

I second what Bouncer has said and will add,if you have done the cam break in or run the engine without the zinc,the damage has already begun.

X3...........I always use a zinc additive when an engine doesn't have a roller cam, and still use Rotella T in the engines that do because it still has a fair amount of zinc in it. I fear if you didn't do any additives up until now HWORRELL might be right. How did you break it in, both initially and for the past 1300 miles?

Don

I initially ran Castrol GTX 10w-40 with an oil/filter change at 250 miles, then around 700 miles and now at 1200 miles. I heard and read synthetics were better so I thought I would give it a try. As far as being flat tappet, I don't know since I didn't build the engine. It is built to stock, so does that mean flat tappet?

Might be just a old wise tail in my old coot head.The summary I have is once you start using a synthetic,you can't change back to regular oil or mix the two.On a trip threw the backwoods of USA needing a qt of oil,that kind of bothers me some.

I read there is no issue with going back and forth, just try to stick with one and keep it. My engine is newly rebuilt so I wanted to stick with something long lasting. I never heard of Brad Penn. Is his oil good? I am going to call my builder to find out about the flat tappet issue. Also, with the initial oil the builder did put in some zinc additive..for the initial break in..
Paul

I understand that going to synthetic too soon after a rebuild doesn't let the rings seat, but again, that might be more myth than truth. And yes, your 283 is a flat tappet cam unless someone put in a retrofit setup, which is not likely since it was a stock rebuild more or less.

Don

This is timely, yesterday a rep came to my shop from Joe Gibbs Racing and explained the deal with the oils. He said the biggest problem with the earlier flat tappet motors is the lack of zinc because zinc messes with the catalitic converter. There is an API rating on the back of quarts of oil, the API is a spec that they have to meet, castrol API type SM is the same as valvolen API type SM etcetc, there is some proprietory differences, kendall makes thiers green ok? Type SM the government specs no zink. That is the stuff taht whiped the cams. The newest generation is API type SN, that stuff has a detergent molecule that finds the additive you put in there and washes it right out!
You need to find oil specifically made for you hot rod. I stock and use Joe Gibbs oil (it was coincidence that i had thier stuff in stock), they offer both synthetic and conventional for hot rods. Go to thier website and read up on the HR series(hot rod) HR-1, HR-2 are both conventional oils; HR-3 & HR-4 are synthetic.
He really got my attention when he said the newer blend of oils will remove any additive that we put in there.

I just drove to a place in Sc...in the boondocks (interesting drive, even got lost) and picked up some Brad Penn 10w-40 oil (place called Steve's Head Shop, they build racing engines)...also picked up some wix filters. The BP has zinc added. I am hoping this oil will be good. Son't know much about Joe Gibbs oil. I will have to read about it..

The Brad Penn will be fine,all the racers around here use that or Joe Gibbs. Just another note Valvoline did have an racing oil that had the zinc,or at least they did 2 years ago when we where running the 305 sprint car which had a flat tappet cam. I can't remember the specifics on it but it cost more than the regular valvoline racing oil and it had printed on the front of the bottle "Illegal for street use" and I think it also had "not for sale in California" Even with using that oil I still added a bottle of G.M.'s EOS from my stock. "When I heard it was gonna become unavailable I bought up all I could find."

oil mixs do not really work . i start every new engine with brad pen or joe gibs .break in oil . it has more zinc the plane race oil . brad or joe break in oil . on start up flat lifter cams to help with break in time its a must ...that i know the engine i machine and build gets break in oil on start up...... zinc is not bad thing alot of the rollers i build i use hi zinc oil in them as there more parts long as there is no cats on the EX as a dealer for both oils brad and joe every engine leave with a case of oil.most all zinc packs you add to oil will not work or zink can not bond to parts if oil has detergente in it .thats why its better to buy a break in oil so you will not have oil clash

I suppose it is too late for a break in oil.. Lesson learned. I will continue to use Penn until they stop making it... Now, what to use in my 85 GT witht he rebuilt 5.0? It has a roller cam and is completely rebuilt. Nothing fancy, just rebuilt to stock as I wanted to keep it all stock. It has CATs unlike my CJ5 with the 283. I am guessing some sort of break in oil..then synthetic?

I think I would do the Brad Penn break in oil and then move on to Mobil 1 10w30 or such on that 5.0.

The mustang has CATS, so the extra zinc may pose a problem. I think they have a special oil for cars with CATS. What is a good break in protocol i.e. oil changes and rpms..speed, start stop,etc...to break in a new engine. The 5.0 is stock and I want it to run another 160K+ without any problems. The person who rebuilt the engine said it looked really good for the miles it had, hardly any wear. Probably could have got 250K+ more...
Thanks,
Paul

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Originally Posted by 1gary

Might be just a old wise tail in my old coot head.The summary I have is once you start using a synthetic,you can't change back to regular oil or mix the two.On a trip threw the backwoods of USA needing a qt of oil,that kind of bothers me some.

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Gary, that is defintely NOT true. There are so many myths and old wive's tales about synthetic oils it makes me laugh when I hear some of the things being said. I may be stirring the pot here but another is having to wait until so many miles to let piston rings seat before changing over to syn oil. That might have been the case several decades ago but in most cases piston ring technology has advanced and materials used have changed in those several decades. Did you know that high end cars like Ferraris, Mercedes-Benz and Corvettes, to name just a few, leave the factories with synthetic oils in the engines? I always use synthetic oil on the piston skirts and the rings when assembling a new engine and I've never had ring seating problems. I use synthetic oils in every vehicle we own, the car, the F-150 and the Harleys but I also don't own anything with a flat tappet cam either, they're all roller tappets.

Mike

Our daily drivers have their oil changed with blended synthetic. What'z up with that?

Got the Brad Penn in and the new Wix filter also lubed up all shackles, u joints, tie rods/ball joints, and chassis pivot points.... Took it for a drive. Next project is to possibly get a Holley Truck Avenger 470cfm instead of the current Edlebrock.